I have a long term plan of building upwards (a second floor on top of my 1939 Cape Cod). Problem is I may not be able to do this right now but my old roof already leaks. It has two layers of shingles and I was told by roofers that it needs to be replaced soon. I don't want to spend a bunch of money for a new roof if I'm going to be destroying it relatively soon (in a few years?). So my options are to replace the roof myself or to just fix the leaks. There are missing shingles and some soft planks and some leaks around the chimney but that's about it.

7 Answers
7

Everyone has given good advice, but the ultimate decision is probably going to depend on the total cost and real time before you plan to add a full second story. I have done dozens of roofs in my time and can give you the following considerations.

A new roof is probably going to cost you around $300 to $350 per square (10ftX10ft or each 100 square feet) for a complete strip, 6 feet of ice/water shield and new 30 yr shingles. Not knowing the size of your roof and pitch, I can't give you a real good guess, but a simple 24X30 cape with a chimney, no crickets or tricky valleys usually runs around 3 to 4 grand. Any good roofer is going to insist that any damaged or rotting roof shiething be replaced while it is stripped, adding more cost. Don't count on using the old roof structure when you remodel. Raising a roof under a new wall system can be very expensive and I suspect you have an original rafter system and board sheithing. Your new roof will want to be of the newest materials and techniques such as trusses, tounge and grove sheathing, soffit and ridge vents etc. A second story is a huge investment and in my humble opinion, very wise to do it all new.

As far as possible repairs to your old existing roof, you may be able to replace some shingles in the field easily, and repair the leaks around the chinmey with a good coat of blind nailing cement or even remove a couple of feet of shingles and treat the area with Grace ice and water shield then reshingle that small area. Obviously, we can't see or judge the general condition or continued life expectancy of the existing roof. I would strongly suggest you stop the water ASAP as Tester is right on saying a couple years of water can cause you a lot of other problems. Good Luck

It all depends on why those leaks appeared. If that happened because some shingles were defective, got broken by some falling objects or just blown away because they were not hold in place firmly you could consider replacing just those shingles. But if they are so old that their lifetime is ending you risk having to replace more shingles as they continue to age and in that case it could be more efficient to replace them all at once.

Also don't forget that the zone around the chimney is very prone to leaks because of house deformation so the leak aroud the chimney doesn't mean world comes to an end, it just needs prompt repairing.

If you aren't going to do your long term second story plan within the next 5 years, then there's no question - simply replace the roof. Patch jobs, especially when there's already signs of damage, and the roof has already been reshingled once, will not last more than a year or two.

If you are going to expand in the next year or two, then you might consider simple repairs, but it's a lot of work finding and fixing every leak.

Also, check with your local codes. While it's almost never advised, some places do allow a third layer of shingles, and that may be enough to hold you off until you do the expansion.

Last spring a raccoon tried to make a nest in our roof. She didn't get through the sheathing, but she did tear out a lot of rotten shingles.

The owner wanted to save money, so they did it themselves. 4 adults (landlord, landlady, their daughter, her boyfriend), a little scaffolding, a nail gun, a chop saw, and many stacks of cedar shingles.

They would strip the shingles off a section, and fix sheathing, add tar paper or whatever, then reshingle. At night they covered exposed areas with tarps.

It took them much longer than they planned. Soon the weather turned stormy. The wind tore off the tarps and the rain came in the attic. One morning we woke up to a drooping ceiling, dripping steadily. It missed my wife's wedding dress by a few inches.

Now they had a new set of problems: standing water to remove from the attic, ruined roof insulation, water damage to the ceiling.

Learning a lesson, they got diligent about securing the tarps at the end of the day. That meant more of their time and energy going to tarping that could have gone to roofing. Since they were much slower than pros, they spent more days on the job, so they did a lot of retarping. There were a few windstorms during that period, and in the evening they'd drive by to check on the tarps. (More time & energy.)

They trimmed the cedar shingles on a chop saw. They seemed to spend a lot of time passing shingles up, measuring them, passing them down, cutting them, and passing them up again. I think pros use a roofing hatchet to do this quickly, but they didn't have that skill.

The roof on this house is complex, due to two additions over the years. They spent a lot of time on the valleys.

At one point the young couple had an argument and he fell off the roof. He was OK, but scared. That slowed the work down even more.

It took a total of 6 weeks. I would guess that a team of pros could have done it in 4 days. That would have meant a lot less time applying tarps and cleaning up water.

sound like u better get out the rolling magnet and metal detector so the kids don't step on rogue nails.
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shirlock homesJan 14 '11 at 7:32

They already did that (diy.stackexchange.com/q/3185/80) and picked up a lot of nails, but we still find some occasionally. We don't walk around barefoot in the grass any more, and miss it. :-(
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Jay BazuziJan 14 '11 at 18:23

Seriously, find someone that has a metal detector and do a sweep of the yard. It works great.
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shirlock homesJan 14 '11 at 20:53

Ultimately the decision is going to be based on cost and how long the work has to last.

You need to get three quotes for both the repair and the replacement options. With the repairs you also need to know how long they'd be expected to last. Take this information and factor in your long term plan of building upwards to make the final decision.

If the repair will last until your plan of extending upwards comes to fruition then the repair is the way to go. If however, you'd need to repair again before then you might have to look more seriously at replacing the roof.

If you can handle it yourself you could save some money, if not make sure you find a good contractor to do it don't just select the cheapest.

If you just fix the leaks, you'll probably spend more time in the future fixing more leaks. The best way to truly fix the leaks is to replace the roof. You'll find that water can do a lot of damage in two years, so it might actually save you money (and some headaches) to fix the roof properly now.

You might actually be able to use the roof when you expand upwards, I have seen people simply raise the existing roof and use it in the expansion. This may depend on the size of the roof, the shape of the roof, and the scope of the expansion, but it can be done in some cases.

First you need to find out if that second story or floor is going to be permitted. That could reduce your problem to one that is non-problematical.

That said, sometimes a decision such as you are facing boils down, simply, to which is the more readily accomplished and which cannot be done without least consequences. In most cases, keeping water out sooner takes preference over (hopefully) keeping water out at some future, as yet undetermined date.